A CCD image sensor (Charge Coupled Device Image Sensor) is used in an image scanning apparatus of an image forming apparatus. Since the allowable upper limit temperature of the CCD image sensor is about 65 degrees and is low as compared with another IC (Integrated Circuit), temperature countermeasures are required.
In recent years, the engine speed of an image forming apparatus becomes high, and the fixing temperature of a fixing device becomes high. Thus, the temperature of the CCD image sensor also becomes high by radiation heat from the fixing device. As countermeasures against this, a method of cooling the CCD image sensor by a cooling FAN is known. However, in this method, the installation area of the FAN and the power for driving the FAN must be secured, and the cost is high.